1. Field of the Invention
Embodiments of the invention described herein pertain to the field of aerial cable rail systems. More particularly, these embodiments enable the movement of objects within two-dimensional space.
2. Description of the Related Art
An aerial cable rail system is a system based on an elevated cable or line, along which objects are transported. Existing cable rail systems have relied on large fixed structures and/or complex control systems in order to facilitate the movement of objects. These systems fail to satisfactorily achieve the full spectrum of ease of control, compact storage, ease of transport, speed, load bearing, extensibility, maintainability and platform stability.
Any number of coordinate systems can be used in order to describe the path of an object as it moves through space. This document uses the terms Z-axis and Y-axis to denote vertical and horizontal directions respectively.
In U.S. Pat. No. 6,199,829 a device is described that follows a line. There is no mechanism for altering the Z-axis displacement of the mechanism moving along the line. The device is self propelled and is heavy.
In U.S. Pat. No. 5,113,768 a device for transporting a camera along a cable is described. The device must be secure enough to carry not only a camera but also a human photographer. The device is limited in the amount of Z-axis displacement that can be effected.
In U.S. Pat. No. 4,864,937 a point A to point B cable rail is described. The device possesses no means to descend in the Z-axis other than by placement of poles. The poles supporting the structure are placed at fixed heights in order to avoid objects on the ground.
In U.S. Pat. No. 6,145,679 a device is described that uses balloons to provide support for a highline. Items are transported along the highline. The balloons may be raised or lowered but are cumbersome in enclosed environments and stadiums where they would block the view of spectators. In addition, the speed at which items could be transported would be fairly slow since a balloon would have a large surface area and would not be capable of rapid horizontal movement.
In French Patent No. 992,069 a device is described which has no means for controlling the arc of travel of the supported object since all control is manual. In addition, no means for conveying messages or advertisements are contemplated and it appears that the device is intended for industrial operations where the stability of the supported object is of little concern.